Pandas SQL Query: Create a boolean series selecting rows with one or more nulls from locations file

Last update on May 28 2022 13:38:01 (UTC/GMT +8 hours)

Pandas HR database Queries: Exercise-13 with Solution

Write a Pandas program to create a boolean series selecting rows with one or more nulls from locations file.

LOCATIONS.csv

Sample Solution :

Python Code :

import pandas as pd
pd.set_option('display.max_rows', 500)
pd.set_option('display.max_columns', 500)
employees = pd.read_csv(r"EMPLOYEES.csv")
departments = pd.read_csv(r"DEPARTMENTS.csv")
job_history = pd.read_csv(r"JOB_HISTORY.csv")
jobs = pd.read_csv(r"JOBS.csv")
countries = pd.read_csv(r"COUNTRIES.csv")
regions = pd.read_csv(r"REGIONS.csv")
locations = pd.read_csv(r"LOCATIONS.csv")
print(locations.isnull())

Sample Output:

    location_id  street_address  postal_code   city  state_province  	  country_id
0         False           False        False  False            True 		False  
1         False           False        False  False            True 		False  
2         False           False        False  False           False 		False  
3         False           False        False  False            True 		False  
4         False           False        False  False           False		False		   
5         False           False        False  False           False 		False  
6         False           False        False  False           False 		False		 
7         False           False        False  False           False		False   
8         False           False        False  False           False 		False  
9         False           False        False  False           False 		False  
10        False           False        False  False            True 		False  
11        False           False        False  False           False  		False 
12        False           False        False  False           False 		False  
13        False           False        False  False            True  		False 
14        False           False         True  False            True  		False 
15        False           False        False  False           False 		False  
16        False           False        False  False           False  		False 
17        False           False        False  False           False 		False  
18        False           False        False  False           False 		False  
19        False           False        False  False           False  		False 
20        False           False        False  False           False  		False 
21        False           False        False  False           False 		False  
22        False           False        False  False           False  		False

Click to view the table contain:

Python Code Editor:

Structure of HR database :

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Previous: Write a Pandas program to create and display a boolean series, where True for not null and False for null values or missing values in state_province column of locations file.
Next: Write a Pandas program to count the NaN values of all the columns of locations file.

Python: Tips of the Day

Find current directory and file's directory:

To get the full path to the directory a Python file is contained in, write this in that file:

import os dir_path = os.path.dirname(os.path.realpath(__file__))

(Note that the incantation above won't work if you've already used os.chdir() to change your current working directory, since the value of the __file__ constant is relative to the current working directory and is not changed by an os.chdir() call.)

To get the current working directory use

import os cwd = os.getcwd()

Documentation references for the modules, constants and functions used above:

The os and os.path modules.

The __file__ constant

os.path.realpath(path) (returns "the canonical path of the specified filename, eliminating any symbolic links encountered in the path")

os.path.dirname(path) (returns "the directory name of pathname path")

os.getcwd() (returns "a string representing the current working directory")

os.chdir(path) ("change the current working directory to path")

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